A20 is a wireless module that combine GPRS and WiFi, also it supports camera connection. It uses ESPRESSIF’s WiFi IC ESP8285 for the WiFi function.A20’s GPRS module and WiFi module can work separately, be powered separately. This is a good solution for your IoT device to connect internet all the time no matter where it is. You can choose the following working model to suit your project:

Only GPRS. For this model, only provide power for GPRS part, then use MCU to control the GPRS by serial port.

Only WiFi. Just like the only GPRS, only provide power for WiFi part, use MCU to control WiFi by serial port.

WiFi and GPRS. Use 2 serial port to control WiFi and GPRS separately.

WiFi as MCU to control GPRS. Under this model, you can use WiFi IC ESP8285 as MCU to control GPRS. Because there is only one two-way serial port, so user need to program ESP8285.

Pin map

Pin Number

Pin name

Explanation

1

CAM_Y1

Camera data Y1

2

CAM_Y2

Camera data Y2

3

CAM_Y3

Camera data Y3

4

CAM_Y4

Camera data Y4

5

CAM_Y5

Camera data Y5

6

CAM_Y6

Camera data Y6

7

CAM_Y7

Camera data Y7

8

PWR_KEY

Power, keep >1.9V for 2 secs the camera will power on, after that keep it on or off, the camera will continue, this pin only requires voltage, no need real power supply.